Why VAR isn't working as usual for West Ham vs Brentford as Premier League step in to explain

Semi-automated offside technology was not in-play as West Ham kicked off against London rivals Brentford - the Premier League has confirmed.

VAR instead used virtual offside lines - as seen during previous seasons - as a result. The change came as a result of the global Amazon Web Services outage on Monday, which has impacted more than 1,000 companies and millions of people worldwide.

An announcement was made by the Premier League Match Centre just four minutes ahead of kick-off at the London Stadium. A notice posted on X, read: "Due to the impact of today's global AWS outage, this evening's match will begin without the use of Semi-Automated Offside Technology (SAOT).

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"If required, the VAR will use virtual offside lines, as in previous seasons, to determine an offside decision. If SAOT becomes available during the game, it will be implemented when appropriate."

It was confirmed at the start of the second-half that SAOT was available. Andy Madley was in charge of officiating the game in question, as Craig Taylor and Nicholas Hopton attended as assistant referees. Thomas Bramall was the fourth official, while Jarred Gillett operated VAR and Tim Robinson was assistant VAR.

Semi-automated offside technology has been used in the Premier League since mid-April and was also used in the FA Cup last season.

It is said to place virtual offside lines more efficiently by utilising optical player tracking. SAOT also produces the virtual graphic that appear in-stadium and on broadcasts.

However, it does not affect the accuracy of decisions. SAOT is also responsible for the virtual graphic that appears in-stadium and on live broadcasts.

The league developed the system in collaboration with Genius Sports and Professional Game Match Officials (PGMO).

Genius Sports appear to have migrated their onside infrastructure to the AWS Cloud last year, as per a blog post from SortServe - the company which claims to have partnered with Genius Sports for the migration.

It's been a challenging start to the Premier League - for both Brentford and West Ham. The Hammers headed into Monday night's fixture in a lowly 19th place in the league table as a result of just one win, one draw and five losses from their opening seven.

It appears to be seen as to whether new boss Nuno Espirito Santo can turn the tide in the capital, or if the state Graham Potter left the club in before his dismissal is too big of a task to overcome.

Brentford, meanwhile, headed into the clash in 16th place, with two wins, one draw and four losses from the same amount of matches. The side are still adapting to life under Keith Andrews, who was appointed after Thomas Frank made the decision to take up tenure with Tottenham, while they lost a number of their major players this summer, such as Bryan Mbeumo and Yoane Wissa to name a couple.